I. Field
The present disclosure relates generally to communication, and more specifically to techniques for performing phase correction for wireless communication.
II. Background
In a wireless communication system, a transmitter typically processes (e.g., encodes and modulates) traffic data to generate data symbols. For a coherent system, the transmitter multiplexes pilot symbols with the data symbols, processes the multiplexed data and pilot symbols to generate a radio frequency (RF) signal, and transmits the RF signal via a wireless channel. The wireless channel distorts the transmitted RF signal with a channel response and further degrades the signal with noise and interference.
A receiver receives the transmitted RF signal and processes the received RF signal to obtain samples. For coherent detection, the receiver estimates the response of the wireless channel based upon the received pilot and derives a channel estimate. The receiver then performs detection with the channel estimate to obtain estimated data symbols, which are estimates of the data symbols sent by the transmitter. The receiver then processes (e.g., demodulates and decodes) the estimated data symbols to obtain decoded data.
The receiver typically estimates frequency error at the receiver. This frequency error may be due to difference in oscillator frequencies at the transmitter and receiver, Doppler shift, and so on. The receiver may remove the frequency error from the samples and then perform detection on the frequency corrected samples. However, there is typically residual error in the frequency error estimate. This residual error results in phase error in the frequency corrected samples, and the phase error may degrade performance.
There is therefore a need in the art for techniques to perform phase correction for wireless communication.